[PDF] - Users C.W. Johnson, Univ ersit y of Glasgo w, Glasgo w, PDF Document

SLIDE 1 Users C.W. Johnson, Univ ersit y

f

Glasgo w, Glasgo w, G12 8QQ. Scotland. johnson@dcs.gla.ac.uk, h ttp://www.dcs.gla .a c.uk/ johnso n Octob er 2001 CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001 1

SLIDE 2 What is HCI?

1940's:
Ergonomics

fo cuses

n

study

f

w

rk.
1950's

& 1960's:

fo

cus

n

Human F acto rs

f

machine interaction.

1980's

& 1990's:

fo

cus

n

Human Computer Interaction.

2000
n:
back

to human facto rs

f

machine interaction;

ubiquitous

computers emb eded in

ther

devices. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 3 Users

What

is a `t ypical' computer user?

What

w

uld

mak e them happ y & p ro ductive? CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 4 Users

What

do y

u

think

f

when y

u

use a computer?

Designer User System model Mental model The System (plus documentation) Constructs Interacts with

Users

develop mental mo dels

f

the system.

This

is dierent from the designers mo del.

It

also diers from their mo del

f

y

ur

mo del. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 5 P erception

W

e detect signals in

ur

environment.

Infra-red

ey e tracking. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 6 P erception

What

w e detect is aected b y:

absolute

and relative signal strength;

anticipation
f

the signal;

signal

to noise ratio.

Links

b et w een p erception and cognition:

users
ften

p erceive signals;

but

fail to interp ret them;

r

understand their semantics.

Anticipation

aects p erception. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 7 Physiology

Physical

attributes aect abilit y to use devices.

Horizontal plane +5 degrees

10 degrees
15 degrees
30 degrees

Normal line of sight

RSI,

Muscosk eletal injuries etc. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 8 Physiology

Designers

also mak e assumptions ab

ut

physiology:

average

p erson is not 1.8 meters tall

average

p erson do es not w eigh 100kg

no

r is their nger span 21cm.

If

w e designed fo r the average who w

uld

w e exclude? CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 9 Cognition

Ho

w do users think ab

ut

the systems they use?

Dierent

emphasis

n

short and long term memory.

Exp

erts w

rk

at a skilled level;

if

something go es wrong w e might use some rules;

if

all else fails try general kno wledge. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 10 Environment

External

impact

n

cognition, p erception and physiology .

What

can y

u

control?

heat,

noise, vib ration, colleagues?

don't

w

rk

next to a p rinter... CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 11 Culture

Globalisation
r

fragmentation?

Japanese

version

f

Microsoft W

rd:
to
k

2-3 y ea rs to develop;

team
f

lo cal p rogrammers;

T
ky
usabilit

y lab.

Cultural

diversit y within a nation (US, Scotland?). CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 12 Age

By

2008, will b e mo re p ensioners than scho

lchildren.
Chr
nolo

gic al ageing:

natural

rate at which w e lose

ur

faculties;

ma

y not b e able to see so w ell etc.

F

unctional ageing:

rate

b ey

nd

the chronological ageing;

can

b e asso ciated with w

rkplace

injuries. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 13 Gender

W
men

have b etter spatial a w a reness?

Gender

related terminology?

`kill'

a p ro cess

r

`ab

rt'

a p rint job.

Men

ma y b e b etter at interrupt handling?

Thematic

vagab

nding

and encysting. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 14 Disabilit y

Key

concept

f

ac c essibility.

Screen

readers and b raille displa ys.

W
rd

p rediction systems.

Scripts

based communication.

Many

technologies transfer into the mass ma rk et. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 15 Summa ry

Users

a re not designers.

Physiology

, P erception, Cognition.

Environment,

Culture, Age, Gender. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001

SLIDE 16 F urther Reading \In the ligh t

f

the scien tic evidence, pregnan t w

men

do not need to stop w

rk

with VDUs. Ho w ev er, to a v

id

problems caused b y stress

r

anxiet y , w

men

who are w

rking

with VDUs should b e giv en the

p-

p

rtunit

y to discuss their concerns with someone adequately informed

f

curren t authoritativ e scien tic information and advice." (Health and Safet y Executiv e)

Shneiderman
n:
human

diversit y , pp 18-27;

individual

and so ciet y 585-600. CS-1Q: HCI (Lecture 1) c

C.W.

Johnson, 2001